The present invention relates to electrical connectors used in hostile environments where radiation from the current carrying connector elements can build up potentially dangerous voltages on surrounding surfaces. In one example of the application of the invention in inertial guidance systems, there are many signals that must be carried through connectors that can be interrupted or impaired by potentials loose in the connector environment. The inertial guidance system is often exposed to particle radiation that can cause secondary emission of the negatively charged electrons from the connector pins. Their absence causes a positive charge on the pins which causes unwanted current. This current can disrupt the information carried by conductors of the connector pins. Connectors in other environments such as power plants are exposed to radiation that can produce emission from current carrying connector pins with the same deleterious effects.
In addition to the need to protect against voltage build up effects, connector bodies are subject to high temperatures during, for example, the vapor phase soldering of the connector pins to circuit boards that they are mounted to. The high temperatures can cause the plastic connector housing to thermally deform. Such change in physical shape can lead to the connector being unable to mate with corresponding connectors of the opposite gender.
In sensitive instrument applications where they are intended to be used in hostile environments, it is common to spray or vacuum deposit the assembly of instruments with protective coatings such as Union Carbide's Parylene. The coating can work its way into the connector housing and to the connector pins where it can prevent electrical contact from being made.